PHP does not directly support wildcard searches in arrays, but can be implemented through fnmatch(), preg_grep() or custom functions. 1. fnmatch() supports shell-style wildcards, such as matching arbitrary characters, ? Match a single character, which is suitable for Unix systems and Windows environments in PHP 8; 2. preg_grep() uses regular expressions to provide more flexible pattern matching, such as /a/ matching elements containing a; 3. Custom functions can convert wildcards into regular expressions to implement specific rules, such as converting them to .* for matching. In addition, attention should be paid to performance optimization, case processing and special character testing.

When you're working with PHP arrays and need to search for elements that match a certain pattern, wildcards can be helpful. However, PHP doesn't support wildcard searches in arrays directly out of the box like some other languages ??or databases might. You'll need to implement custom logic depending on your needs.

Here are a few practical ways to use wildcard-like behavior when searching through PHP arrays.

Using fnmatch() for Wildcard Matching

If you're familiar with shell-style wildcards (like * for any number of characters and ? for a single character), fnmatch() is a great tool. It works well on Unix-based systems but may not behave the same way on Windows unless you're using PHP 8.

 $array = ['apple', 'banana', 'cherry', 'date'];
$matches = array_filter($array, function($item) {
    return fnmatch('*a*', $item); // Matches any item containing 'a'
});

• * matches zero or more characters.
• ? matches exactly one character.
• Use this inside array_filter() for filtering array items.

Keep in mind: This function is case-sensitive by default. If you want case-insensitive matching, convert both strings to lowercase first or use the FNM_CASEFOLD flag:

 fnmatch('*a*', $item, FNM_CASEFOLD);

Using Regular Expressions with preg_grep()

If you're comfortable with regex, preg_grep() is another powerful option. It allows you to search an array using regular expressions, which gives you much more flexibility than simple wildcards.

 $array = ['apple', 'banana', 'cherry', 'date'];
$matches = preg_grep('/a/', $array); // Finds all items containing 'a'

Some useful patterns:

• /^a/ – starts with 'a'
• /a$/ – ends with 'a'
• /a.*z/ – contains 'a' followed by any characters then 'z'

This method is especially handy if you're doing complex pattern matching.

Building a Custom Wildcard Search Function

If neither fnmatch() nor preg_grep() fits your exact needs, writing a custom function can help. For example, if you want to translate a basic wildcard string into a regex pattern:

 function wildcard_match($pattern, $subject) {
    $pattern = str_replace(['\*', '\?'], ['.*', '.'], preg_quote($pattern, '/'));
    return (bool) preg_match("/^{$pattern}$/i", $subject);
}

$array = ['apple', 'banana', 'cherry', 'date'];
$matches = array_filter($array, function($item) {
    return wildcard_match('*an*', $item); // Matches banana, etc.
});

This approach lets you define your own rules for how wildcards should behave and can be extended easily.

A Few Notes Before You Go

• Performance matters — looping through large arrays repeatedly can get slow.
• Consider pre-filtering or caching results if you're doing multiple searches.
• Make sure to test edge cases, especially around uppercase/lowercase handling and special characters.

Basically that's it.

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